Compact tree clamp and automatic sequence control for a tree length harvester

ABSTRACT

A tree clamp, especially for a tree length harvester, having a compact arrangement of a movable jaw which folds partially inside of a fixed jaw and has a pivoted section to clamp the tree. The movable jaw and its pivoted section also grasp the butt end of the tree and lift it out of the teeth of the fixed jaw at the end of the processing step. The tree is then released and free to roll into a storage rack. An automatic sequence control is provided that includes a pivoted plate on the clamp which is depressed by the tree to initiate processing steps without requiring the operator&#39;&#39;s attention.

United States Patent 1191 1111 3,

McKenzie [4 Dec. 9, 1975 [5 COMPACT TREE CLAMP AND 3,709,267 1/1973Kurelek 144/3 D x AUTOMATIC SEQUENCE CONTROL FOR A 3,720,248 3/1973Mellgren 144/3 D X 3,734,152 5/1973 Shields 144/3 D TREE LENGTHHARVESTER Ian McKenzie, Lambeth, Canada Clark Equipment Company,Buchanan, Mich.

Filed: Mar. 18, 1974 Appl. No.: 452,171

Inventor:

Assignee:

US. Cl. 144/3 D; 144/2 Z; 144/34 R; 144/309 AC; 269/31 Int. Cl. A01G23/08 Field of Search 144/2 Z, 3 D, 34 R, 309 AC, 144/34 E; 269/13, 31,58

References Cited UNITED STATES PATENTS Primary Examiner-Frank T. YostAssistant Examiner-W. D. Bray Attorney, Agent, or FirmJack E. Toliver[57] ABSTRACT A tree clamp, especially for a tree length harvester,having a compact arrangement of a movable jaw which folds partiallyinside of a fixed jaw and has a pivoted section to clamp the tree. Themovable jaw and its pivoted section also grasp the butt end of the treeand lift it out of the teeth of the fixed jaw at the end of theprocessing step. The tree is then released and free to roll into astorage rack.

An automatic sequence control is provided that includes a pivoted plateon the clamp which is depressed by the tree to initiate processing stepswithout requiring the operators attention.

6 Claims, 5 Drawing Figures U.S. Patent Dec. 9, 1975 Sheet 1 of 43,924,667

US Patent Dec. 9, 1975 Sheet 2 of4 3,924,667

US. Patent Dec. 9, 1975 Sheet 3 of4 3,924,667

FIG. 3

FIG. 4

COMPACT TREE CLAMP AND AUTOMATIC SEQUENCE CONTROL FOR A TREE LENGTHI-IARVESTER BACKGROUND OF THE INVENTION The invention pertains to theart of tree processors or mobile tree harvesters and especially the typereferred to as tree length harvesters having a felling head which shearsa tree at the ground and holds it upright and then pivots it to ahorizontal position for delimbing and topping.

A tree length harvester of this type is disclosed in the copendingapplication US. patent application Ser. No. 363,936, filed May 25, 1973,claiming priority based on Canadian application Ser. No. 163,290 filedFeb. 6, 1973, by inventors Ian McKenzie et al and assigned to theassignee of the present invention. Its operation is in a sequence thatpermits the felling head to return for a second tree while the cut treeis being delimbed and topped. This substantially reduces the over-allprocessing time per tree and increases the productivity of the machine.

In order to cycle the delimber while returning the felling head for asecond tree, it is necessary to clamp the tree. But no clamp hasheretofore been devised that functions properly on a tree lengthharvester and without interfering with the simultaneous processing oftrees.

DESCRIPTION OF THE PRIOR ART One difficulty is that the tree must betransferred from the felling head to the clamp. The combined stackheight of the felling head and clamp becomes a factor in permitting thedelimber to start out close enough to the butt end of the tree. When itfails to get behind all of the limbs, the trees must be partiallydelimbed by hand. To deal with this problem, the clamp should be asnarrow as possible. The delimber can then be started very near the upperclamp on the felling head when the tree is laid in its horizontaldelimbing position. This, however, requires the clamp to be very narrow.

Another problem has been the tendancy of the delimbed and topped tree tohang up after the delimber has cleared. That is, the tree is preventedfrom rolling laterally into the storage rack after being delimbed andtopped. This stops the delim'ber from being recycled until the tree canbe removed. Interruptions such as this cannot be tolerated in such ahigh production machine.

SUMMARY OF THE INVENTION A compact tree clamp, especially for a treelength harvester, has a fixed jaw and a movable jaw closing on the fixedjaw. The fixed jaw has an arcuate tooth section. The movable jaw ispivoted at two locations. A first pivot is on the fixed jaw and allowsthe movable jaw to be partially folded or collapsed into spaced framesections of the fixed jaw. When collapsed in this fashion, the tree isclamped in the teeth of the fixed jaw and prevented from axial movementby an arm of the movable jaw pivoted about a second pivot on theopposite side of the tree axis from the first pivot.

After delimbing and topping, the movable jaw is tilted up about thefirst pivot while the arm continues to hold the tree. This raises thebutt end of the tree and shifts it laterally toward the storage rack.The arm is pivoted about the second pivot unclamping the tree to roll itinto the storage rack.

2 In the application on a horizontal tree harvester, the clamp becomes afunctional part of the over-all machine when it is considered that thefelling head must transfer the tree to the clamp before delimbing canpro- 5 ceed and the felling head returned for a second tree.

In such a harvester, the tree clamp serves the function, not only ofsecurely clamping the tree for delimbing, but also provides thecapability of simultaneous processing which is fundamental to the highproductivity of this type of harvester.

Consistent with this objective and method of processing full lengthtrees, the present invention is viewed as a tree length harvesterautomatic sequence control including means (a pivoted plate) on themovable jaw actuated by a tree deposited on the fixed jaw, a fluidpressure source, an actuating circuit connected to said source includinga control element (sequence valve), a first cylinder for pivoting thearm of the movable jaw actuated by the control element in one positionto close the arm, means (first valve) in the actuating circuit operatedby the arm when closed initiating the delimbed cycle, a second means(second valve) operated at the end of the delimber stroke to shift thecontrol element to a second position, a second cylinder actuated in saidsecond position to tilt the movable jaw, means (third valve) operatedwhen the second cylinder is extended to cause said control element tooperate the first cylinder and to open the arm releasing the tree whichallows said first means (pivoted plate) to return causing the secondcylinder to lower the movable jaw.

In the preferred embodiment, the movable jaw will have its arm pivotedon an axis parallel to the delimber axis. The entire movable jaw is alsopivoted about a second or main pivot axis on the opposite side of thedelimber axis. The first cylinder is carried on the movable jaw and isoperable to pivot the arm about its pivot axis. The second cylinderextends between the spaced frame of the fixed jaw and is operable forpivoting the movable jaw about its main pivot axis. The arm has aninterior are, which when closed, overlies and partially encloses thetree. The movable jaw carries the pivoted actuating plate in suchposition that as the teeth penetrate the tree, which is forced down fromabove by the arm, the plate is automatically depressed initiating thecycle.

After delimbing and topping, the movable jaw is pivoted about its mainaxis by operating the second cylinder. The actuating plate remainsengaged with the tree and in the depressed condition since the tree isstill clamped by the arm of the movable jaw. The butt end of the tree ismoved upwardly and laterally with respect to the delimber axis. At theuppermost position, the first cylinder is extended to open the arm ofthe movable jaw permitting the tree to roll down into the storage rack.This releases the actuating plate permitting the second cylinder toreturn lowering the movable aw.

It is one advantage of the invention that the tree clamp has a dualcapability. In the one case, the tree is secured against axial movementbetween the fixed and movable jaws while in the other case it is graspedand pivoted out of the fixed jaw by the movable jaw. Thus a principaladvantage of the invention is a clamp that functions both as an axialtree clamp and tree ejection device for positive removal of the treeregardless of the slope on which the machine is operated.

Another advantage for tree length harvesters is that the clamping jawsform a compact arrangement with- 3 out increasing the stack height tothe detriment of the delimber operation.

A major advantage in the over-all function of a tree length harvester isthat higher productivity is achieved because of positive ejection. Thedelimbed and topped tree is quickly and positively ejected to make roomfor the second tree after each delimbing and topping cycle.

A further major advantage is the provision of an automatic sequencecontrol for a tree length harvester in which the tree clamp initiatesthe sequence.

These and other advantages will be readily apparent by referring to thefollowing more detailed description wherein:

DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of a treelength harvester on which the tree clamp is mounted.

FIG. 1A is a partial view of the harvester depicting the motion of thefelling head;

FIG. 2 is a sectional view showing the movable jaw closed upon the fixedjaw in one position and raised in dot-dash lines taken along line 2-2 ofFIG. 1;

FIG. 3 is a partial plan view in the clamp showing the compact orinterleaved relationship of the jaws;

FIG. 4 is a view of the tree clamp on the side from which the tree isreleased; and

FIG. 5 is a hydropneumatic schematic of a portion of the sequencecontrol circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a tree harvesterhaving front and rear sections 12, 14 articulated at 15. The frontsection 12 has a trunnion 16 on which is pivoted a tree length processoror harvester apparatus generally indicated by numeral 17. The apparatus17 includes essentially a felling head 18, a delimber apparatus 19 atree clamp 20 and a storage rack 21. For a more detailed description ofsuch a harvester, reference is made to the aforementioned applicationU.S. patent application Ser. No. 363,936. The felling head 18 is carriedon a boom 22 telescoping within a tubular beam 23 which pivots on thetrunnion 16. The delimber 19 includes a carriage 25 which cradles thetree on a bottom delimber knife (not shown) and has other delimberknives 26 which enfold about or partially encircle the tree. Toppingknives, (not shown) are also on this carriage. The carriage 25 is pulledalong a rail 27 by a cable 28 as the rail itself is propelled to therear on the beam 23 by a cable and rum drive 30. A severed tree held by'the felling head 18 in a substantially vertical position is rotatedupwardly and rearwardly by pivoting the felling head on a boom arm 33actuated by a cylinder 34 (FIG. 1A). In the uppermost position thefelling head positions the tree butt end in the opened tree clamp 20.The delimber knives 26 and the topping knives of the delimber carriage25 will also open to receive the tree. The clamp 20 must now be closedto permit the felling head to return for a second tree and the delimbercarriage to commence its cycle. This is the position of the clamp shownin FIG. 1.

THE TREE CLAMP Referring now to FIG. 2, the tree clamp 20 includes aframe 35 secured to the front of the beam 23. A goose neck portion 37(FIG. 4) extends upwardly in offsetting relationship toward the front ofthe beam so as to position the tree calmp behind the delimber carriage25 in its rearmost position and as close as possible to the felling headin its raised position (FIG. 1A). A fixed jaw 38 is formed on the upperregions of spaced structural plages 40 of the frame 35 extendingtransversely over the beam 23. One side of the jaw 38 provides an armatetooth section 41 adjacent the delimber. The tooth section conformsgenerally to the curve of the cradle or bottom delimber knife of thedelimber carriage which will accommodate trees up to about 15 inches indiameter or as small as about 6 inches on the delimber axis as depictedat 43. A plurality of teeth 42 on the fixed jaw section 41 willpenetrate the tree to hold it securely when clamped against axialmovement.

A movable jaw is pivoted at two places. A pin 53 pivotally carries anarm 51 on one side of the delimber axis and pin 54 on the opposite sidepivotally connects the entire movable jaw between the plates 40. Thepivoted arm 51 of the movable jaw is structured of a pair of elements 55(FIG. 3) having interior arcuate surfaces 56 which overlie the delimbingaxis and when folded or closed toward the tree 43, partially encircle orsurround the butt end of the tree. The elements 55 are spaced closertogether than spaced plates 57 of the movable jaw which in turn arespaced inside of the plates 40 of the fixed jaw such that the arm 51. ofthe movable jaw folds inside the plates 57 which in turn fold inside theplates 40 of the fixed jaw. The elements 55 are bushed on the pin 53carried between the plates 57 of the movable jaw while the plates 57 arebushed on pin 54 carried between the plates 40 of the fixed jawestablishing a compact or interleaved arrangement. Between the plates 40of the fixed jaw and pivotally mounted on the plates 57 of the movablejaw is an actuator plate 60 which rests above the tops of the teeth 42in the lowered position of the movable jaw being held there by a spring(not shown). The function of the plate 60 will be described more indetail hereinafter. Also mounted between the plates 40 of the fixed jawis a pair of cylinders 62, 64. Cylinder 62 is mounted between plates 40below the movable jaw. It is pivoted at its lower end at 65 and at therod end to a bracket 68 on the bottom of the movable jaw. This is thetilt cylinder. Cylinder 64 is mounted between the plates 57 of themovable jaw and is pivotally connected at 68 on its lower end and at 69on the rod end by a pin 70 carried between the elements 55 of the arm 51of the movable jaw. This is the clamp cylinder. The rod of the cylinder64 is extended in the full line position shown in FIG. 2 while the rodof the cylinder 62 is retracted. In this position the arm 51 of themovable jaw will be folded over the tree holding it firmly in engagementwith the teeth 42 on the fixed jaw. The plate 60 will be depressed belowthe tops of the teeth of the fixed jaw by the action of the tree 43being deposited by the felling head (FIG. 1A) on the fixed jaw with thearm 51 raised as depicted in dot-dash lines in FIG. 2.

AUTOMATIC SEQUENCE CONTROL Referring to FIG. 5, the harvester automaticsequence control is diagrammed insofar as it pertains to the clampactuation and its effect on the operation of the processor 17. A sourceof fluid pressure 72 which in the preferred embodiment is air pressure,is connected to a control circuit generally indicated by the numeral 74which controls a hydraulic circuit generally shown at 75 for operatingthe tilt and clamp cylinders 62, 64 in accordance with the processorsequence. The hydraulic circuit 75 includes valves 76, 77 which areoperated by pneumatic motors 78, 79 to direct hydraulic fluid from thepump 80 and under pressure from the accumulator 81 to either extend orretract cylinders 62, 64 in the appropriate sequence as determined bythe pneumatic control circuit 74. Hydraulic fluid is ex: hausted throughvalves 76, 77 to a reservoir 82.

The pneumatic control circuit 74 includes a valve 84 which is connectedto the pneumatic pressure source 72. At the point in the cycle where thedelimber has returned to the start position as shown in FIG. 1 and inreadiness to accept a tree, the valve 84 is positioned so as topressurize a portion of the circuit depicted by dash lines 85, 86 and 87and valves 88, 89 and 90. In this condition the pneumatic motors 78, 79will be vented below the piston through lines 91, 92.

When a tree is loaded on the delimber, the actuating plate 60 on themovable jaw of the clamp will be depressed by the butt end of the treeas described before. This will cause actuation of the valve 84pressurizing another portion of the circuit as depicted in dot-dashlines 93, 94, 95 pressurizin g the motor 78 causing actuation then ofthe portion of the hydraulic circuit including valve 76 which in turncauses the clamp cylinder 64 to extend pivoting the arm 51 down andfirmly clamping the tree into the fixed jaw. A valve 97 is hydraulicallyactuated simultaneously to start the delimber drive (not shown).

After the delimber carriage has traveled beyond the tree and the toppingknives have operated to remove the upper portion of the tree thecarriage will travel to the position of valve 98 mechanically actuatingit to energize another portion of the circuit depicted by solid lines100 and 101. A sequence control valve 102 is pneumatically actuated atthis point to pressurize lines 103 and 104 causing actuation of thepneumatic motor 79 which in turn shifts the valve 77 in the hydrauliccircuit 75 which controls the tilt cylinder 62 causing it to extendpivoting the movable jaw about pivot 54 to the position shown bydot-dash lines in FIG. 2. When this movement is completed and cylinder62 is fully extended, hydraulic pressure will be supplied at 105 to thevalve 90 in the pneumatic circuit causing it to pressurize line 107operating the pneumatic motor 78 so as to shift the hydraulic valve 76causing the cylinder 64 to retract and thus pivot the arm 51 which hasbeen holding the butt end of the tree while the movable jaw is in theraised position. This is depicted in the dot-dash lines also in FIG. 2.

At this point it will be noted by referring to FIG. 2 that the movablejaw has tilted upwardly and laterally of the delimber axis in thedirection of the storage rack 21 (FIG. 1). Thus, regardless of the slopethe harvester may be operating on the degree of incline of the movablejaw in the tilted up position will be more than enough to assure thatthe delimbed and topped tree rolls into the rack 21.

While alternate embodiments of my invention have been disclosed, it willbe understood that these descriptions are for purposes of illustrationonly and that various modifications and changes can be made to myinvention without departing from the spirit and scope of it. Therefore,the limits of my invention should be determined from the followingappended claims.

What is claimed is:

1. In a mobile tree length harvester including means for cutting astanding tree and holding it upright, means for pivoting the cutter andholding means in a vertical plane to orient the tree in a substantiallyhorizontal po- 'sition, means for clamping the tree in the horizontalposition and means for delimbing the tree in the horizontal position,the improvement in said clamping means comprising a movable jaw havingseparate pivoted elements disposable in either a raised or loweredposition, one pivoted to the other on a first axis parallel to thedelimber axis and extending transversely above the delimber axis in thelowered position and the other pivoted about a second axis parallel tothe delimber axis on the opposite side of the delimber axis andextending transversely below the delimber axis in the lowered position,a fixed jaw having a tree receiving section formed by a pair of spacedplates between which the movable jaw is lowerable sufficiently to permitdeposit of the severed tree on said tree receiving section and cylindermeans operable for pivoting said movable jaw about the second axis forlifting the tree out of the tree receiving section of the fixed jaw andmeans operable to pivot the one element of the movable jaw about thefirst axis to hold the tree clamped on the tree receiving section of thefixed jaw in the lowered position of the movable jaw and to release thetree in the raised position of the movable jaw.

'2. The improvement according to claim 1 wherein said fixed jawcomprises an arcuate row of teeth on the plate adjacent the delimbermeans for penetrating the tree and holding it in cooperation with theone element of the movable jaw against axial movement.

3. The improvement according to claim 2 wherein the other element of themovable jaw comprises spaced plates pivoting inside the spaced plates ofthe fixed jaw and said one element pivots between the plates of saidother elemtent.

4. The improvement according to claim 2 where a storage rack fordelimbed and topped trees is positioned on the side of the delimber axisor the pivot axis for both elements of the movable jaw.

5. A sequence control for a treelength harvester having means forcutting a standing tree and holding it upright, means for pivoting thecutting and holding means in a vertical plane to orient the tree in asubstantially horizontal position, means for clamping the tree in thehorizontal position, and means for delimbing the tree in the horizontalposition, the clamping means comprising a fixed jaw adapted to receivethe butt end of a tree to be delimbed, a movable jaw closable on thefixed jaw having separate pivoted elements disposable in either a raisedor lowered position, one pvioted on the end of the other on one side ofthe delimber axis and the other extending below the delimber axis in thelowered position and pivoted on the opposite side, a first cylinderoperable to pivot said one element to clamp and unclamp the tree, asecond cylinder operable to pivot both elements about said other pivotaxis to pivot the movable jaw away from the fixed jaw carrying the buttend of the tree with it, said control comprising actuator means on saidlatter element extending above the bottom of the fixed jaw so as to beactuated when a tree is placed thereon, first means moving from aninitial position in response to actuation by said actuator means tocause said first cylinder to close the one element clamping the tree,second means actuated upon the clamping of said element to start saiddelimber means, third means actuated by the delimber means afterdelimbing the tree for operating said second cylinder to pivot themovable jaw, and fourth means actuated upon pivoting the movable jaw tocause said first cylinder to unclamp the tree permitting it to roll offof said actuator means returning said first means to the initialposition.

6. A sequence control according to claim wherein said first meansincludes a first valve actuated by said actuator means, a fluid motormeans connected to a first source of fluid pressure by actuation of saidvalve, a second fluid pressure circuit including a separate source offluid pressure, valve means in said second circuit responsive to saidfluid motor means for causing said first cylinder to operate the oneelement for clamping the tree, said second means comprising a valveactuated by clamping said tree to start the delimber, said third meansincluding a valve actuated by the delimber clamp the tree.

1. In a mobile tree length harvester including means for cutting astanding tree and holding it upright, means for pivoting the cutter andholding means in a vertical plane to orient the tree in a substantiallyhorizontal position, means for clamping the tree in the horizontalposition and means for delimbing the tree in the horizontal position,the improvement in said clamping means comprising a movable jaw havingseparate pivoted elements disposable in either a raised or loweredposition, one pivoted to the other on a first axis parallel to thedelimber axis and extending transversely above the delimber axis in thelowered position and the other pivoted about a second axis parallel tothe delimber axis on the opposite side of the delimber axis andextending transversely below the delimber axis in the lowered position,a fixed jaw having a tree receiving section formed by a pair of spacedplates between which the movable jaw is lowerable sufficiently to permitdeposit of the severed tree on said tree receiving section and cylindermeans operable for pivoting said movable jaw about the second axis forlifting the tree out of the tree receiving section of the fixed jaw andmeans operable to pivot the one element of the movable jaw about thefirst axis to hold the tree clamped on the tree receiving section of thefixed jaw in the lowered position of the movable jaw and to release thetree in the raised position of the movable jaw.
 2. The improvementaccording to claim 1 wherein said fixed jaw comprises an arcuate row ofteeth on the plate adjacent the delimber means for penetrating the treeand holding it in cooperation with the one element of the movable jawagainst axial movement.
 3. The improvement according to Claim 2 whereinthe other element of the movable jaw comprises spaced plates pivotinginside the spaced plates of the fixed jaw and said one element pivotsbetween the plates of said other elemtent.
 4. The improvement accordingto claim 2 where a storage rack for delimbed and topped trees ispositioned on the side of the delimber axis or the pivot axis for bothelements of the movable jaw.
 5. A sequence control for a tree lengthharvester having means for cutting a standing tree and holding itupright, means for pivoting the cutting and holding means in a verticalplane to orient the tree in a substantially horizontal position, meansfor clamping the tree in the horizontal position, and means fordelimbing the tree in the horizontal position, the clamping meanscomprising a fixed jaw adapted to receive the butt end of a tree to bedelimbed, a movable jaw closable on the fixed jaw having separatepivoted elements disposable in either a raised or lowered position, onepvioted on the end of the other on one side of the delimber axis and theother extending below the delimber axis in the lowered position andpivoted on the opposite side, a first cylinder operable to pivot saidone element to clamp and unclamp the tree, a second cylinder operable topivot both elements about said other pivot axis to pivot the movable jawaway from the fixed jaw carrying the butt end of the tree with it, saidcontrol comprising actuator means on said latter element extending abovethe bottom of the fixed jaw so as to be actuated when a tree is placedthereon, first means moving from an initial position in response toactuation by said actuator means to cause said first cylinder to closethe one element clamping the tree, second means actuated upon theclamping of said element to start said delimber means, third meansactuated by the delimber means after delimbing the tree for operatingsaid second cylinder to pivot the movable jaw, and fourth means actuatedupon pivoting the movable jaw to cause said first cylinder to unclampthe tree permitting it to roll off of said actuator means returning saidfirst means to the initial position.
 6. A sequence control according toclaim 5 wherein said first means includes a first valve actuated by saidactuator means, a fluid motor means connected to a first source of fluidpressure by actuation of said valve, a second fluid pressure circuitincluding a separate source of fluid pressure, valve means in saidsecond circuit responsive to said fluid motor means for causing saidfirst cylinder to operate the one element for clamping the tree, saidsecond means comprising a valve actuated by clamping said tree to startthe delimber, said third means including a valve actuated by thedelimber after delimbing the tree, other fluid motor means, other valvemeans in said second fluid pressure circuit responsive to said otherfluid motor means for causing said second cylinder to operate pivotingthe movable jaw, said third means comprising a pressure responsive valveactuated by said valve of the second means to direct fluid pressure tosaid other fluid motor means causing said second cylinder to pivot themovable jaw, said fourth means including a valve responsive movement ofthe second cylinder to oppositely pressurize said first fluid motorcausing said first cylinder to unclamp the tree.